Silicon nitride films may play an important role in the manufacture of transistors, as a nitride spacer, or in memory, as the floating gate. In order to deposit these films with good step coverage over nanoscale, high-aspect ratio structures, a film deposition called Atomic Layer Deposition (ALD) is needed. ALD is the deposition of a film by sequentially pulsing two or more precursors separated by an inert purge. This allows the film growth to proceed layer by layer and is limited by the surface active sites. Film growth in this manner allows for thickness control over complex structures, including re-entrance features.
Dielectric thin films with low dielectric constants (low k) and low wet etch rate (in diluted HF solution) properties, such as SiCN or SiCON, can be used as spacer materials in front end processes in the semiconductor industry. Most thin film properties cannot meet practical requirements due to poor film composition control, such as hydrogen contamination and/or different bonding states of carbon in the film. Poor conformality of the film deposited on 3D trenches is also known. Accordingly, there is a need in the art for low k and low wet etch rate SiCN, SiCO and SiCON films.